# Cloud Pub/Sub - [Main page](https://cloud.google.com/pubsub) ![[Google Pub Sub steps.png]] # Tech thinks to remember Message queue service. Great to decouple services. Allows for asynchronous configuration. It does not allow for "exactly one delivery", for that use [[Cloud Dataflow]] Each application requires a dedicated subscription to read from a topic. - **Topic** stores messages - **Subscription** enable applications to read messages in a queue You create a topic and will probably also want a subscription: Standard subscription configuration: - pull delivery - 7 days retention - expiration (of the subscription) after 31 days of inactivity - 10 seconds to acknowledge - immediate retry [[Dataflow]] can be used to export the data in a topic into [[BigQuery]] or [[Cloud Storage]]